The principal goal of the Pilot/Exploratory Studies Core (PESC) is to foster high-quality, innovative, investigator-initiated research Translational Research on Cardiac and Skeletal Muscle Dysfunction in Aging and Disease. Such studies may be designed to prevent and/or treat morbidity and mortality associated with cardiac and skeletal muscle weakness and its sequelae. This will be achieved by funding pilot and exploratory studies that have the highest potential In terms of generating data, resulting in influential publications, and culminating in extramural funding. Such studies are thus deemed likely to advance the careers of promising scientists entering this field. Activities of the PESC will contribute to the overall goals of the Arkansas Older Americans Independence Center (OAiC) by strengthening research programs that focus on aging cardiac and skeletal muscle weakness and nutrition as one of the key interventions. By offering pilot grant support and strong mentoring opportunities, the PESC will provide a valuable mechanism for junior investigators to overcome the initial hurdles to securing research funds and to help propel their careers in research intended to improve outcomes for older adults. It will also help us to attract senior investigators from other disciplines to the intersection of research on striated muscle (both cardiac and skeletal) and nutrient supplementation. We are fortunate to have received ten excellent proposals, both from senior, internationally recognized scientists, who are poised to enter this area of investigation, and from exceptional young investigators starting on their career goals. Martin Hauer-Jensen, MD, PhD, an outstanding clinical researcher at the University of Arkansas for Medical Sciences (UAMS), exemplifies the first category; he has proposed to study the physiological basis for restoration of skeletal muscle mass and strength following arginine supplementation in human subjects. Two junior-faculty researchers were also selected: Anna Csiszar, MD, PhD, of the University of Oklahoma, will investigate the effects of arginine supplementation on cardiac and skeletal muscle function in rodents, and Sharda Singh, PhD (UAMS), proposes to study the metabolic changes underlying sarcopenia and ectopic fat accumulation in skeletal and cardiac muscle of aging mice. These three proposals were selected by the Internal Review and Executive Committee members from UAMS and OUHSC. This proposal review committee was guided by the same selection criteria presented in this proposal: high quality of proposed science, translational potential, congruence with the goals of the Arkansas OAIC, likelihood that PESC support will lead to extramural funding, and full utilization of cores RC1, RC2 and RC3.